Reset customer group collection after filtering

[kamilszewczyk]

Without clearing customer group collection, any loops on existing collection will not be filtered

Summary

Add field filtering without clearing the collection (or creating new instance of it) will not actually do anything. Excluding websites should speed up the process of indexing by not requiring retrieval of grouped prices in websites that are excluded.
Without this modification this code doesn't do anything.

Result

With Customer Group # option enabled, any runs of foreach ($this->groups as $group) for example in vendor/algolia/algoliasearch-magento-2/Helper/Entity/Product/PriceManager/ProductWithChildren.php::setFinalGroupPrices should only loop through customer groups that are NOT excluded in the current website scope.

Without the change:

After the change:

[cammonro]

@kamilszewczyk Thank you for identifying this bug! This is a sensible fix and we'll be sure to include it in a future patch release.